Question

calculeaza masa de sare de bucatarie Na Cl care contine 142g clor

Answer 1

          2mol    x  
2Na + Cl2 =2NaCl
            1mol    2mol

M(Cl2)= 2x35,5= 71g/mol
∨= m/M= 142 g/71g/mol= 2mol 
x= 2mol x 2mol / 1mol = 4 mol(NaCl)
M(NaCl)= 23 + 35,5 = 58,5 g/mol
m=∨ x M= 58,5g/mol x 4mol =234 g
Raspuns: m(NaCl) =234 g 

Answer 2

MNaCl=23+35,5=58,5
58,5gNaCl.........35,5 g Cl2
  xgNaCl........... 142gCl2
x=58,5*142/35,5=234g NaCl